KR20240028327A - composition - Google Patents

Abstract

Contains tetrafluoroethylene-based polymer particles, hollow particles, and particles of a predetermined inorganic compound in a predetermined ratio, has excellent dispersibility, low linear expansion coefficient, dielectric constant, and dielectric loss tangent, and excellent thermal conductivity and adhesiveness. Providing a composition capable of forming a molding. It includes first particles of a tetrafluoroethylene-based polymer, hollow second particles, and third particles of an inorganic compound having an aspect ratio greater than 1, and the volume concentration of the first particles relative to the volume concentration of the second particles. is greater than 1, and the ratio of the volume concentration of the third particles to the volume concentration of the second particles is less than 0.6.

Description

composition

The present invention relates to a composition comprising first particles of a tetrafluoroethylene-based polymer, hollow second particles, and third particles of an inorganic compound having an aspect ratio greater than 1.

Recently, in order to cope with the increase in speed and frequency in mobile communication devices such as mobile phones, materials with high thermal conductivity, low linear expansion coefficient, low dielectric constant, and low dielectric loss tangent are required for materials for printed circuit boards of communication devices. Additionally, tetrafluoroethylene-based polymers with low dielectric loss tangent are attracting attention.

In order to obtain materials with better physical properties, compositions containing components other than tetrafluoroethylene polymers are being investigated. Patent Document 1 proposes a powder composition of tetrafluoroethylene-based polymer particles and boron nitride particles.

Japanese Patent Publication No. 2014-224228

Tetrafluoroethylene-based polymers have low surface tension and low affinity with other components. Therefore, in molded articles formed from a composition containing a tetrafluoroethylene polymer and other components, the physical properties of each component may not be sufficiently expressed. The present inventors have proposed a composition capable of forming a molded article with a low coefficient of linear expansion and excellent electrical properties, thermal conductivity, and adhesiveness, and specifically, a composition capable of forming a molded article having these physical properties and having a sufficiently low dielectric loss tangent. I found this difficult to obtain.

The present inventors have found that a composition containing particles of a tetrafluoroethylene-based polymer, hollow particles, and particles of a predetermined inorganic compound in a predetermined ratio has excellent dispersibility, and the molded product has a low coefficient of linear expansion, dielectric constant, and dielectric loss tangent. , it was found to have excellent thermal conductivity and adhesiveness, and in particular, a low dielectric loss tangent, leading to the present invention.

The object of the present invention is to provide such a composition.

The present invention has the following aspects.

[1] Comprising first particles of a tetrafluoroethylene-based polymer, hollow second particles, and third particles of an inorganic compound having an aspect ratio greater than 1, the first particles relative to the volume concentration of the second particles is greater than 1, and the ratio of the volume concentration of the third particle to the volume concentration of the second particle is less than 0.6.

[2] The volume concentration of the first particles, the volume concentration of the second particles, and the volume concentration of the third particles, relative to the total volume of the first particles, the second particles, and the third particles, are in this order As such, the composition of [1] is 40 to 70%, 20 to 50%, 5% or more and less than 30%.

[3] The first particles are particles of a heat-meltable tetrafluoroethylene-based polymer, and the heat-meltable tetrafluoroethylene-based polymer has a melting temperature of 200 to 320°C and has an oxygen-containing polar group. The composition of [1] or [2], which is a meltable tetrafluoroethylene-based polymer.

[4] The composition according to any one of [1] to [3], wherein the first particles include particles of a heat-meltable tetrafluoroethylene-based polymer and particles of a non-heat-meltable tetrafluoroethylene-based polymer.

[5] The composition according to any one of [1] to [4], wherein the average particle diameter of the first particles is 0.01 μm or more and less than 10 μm.

[6] The composition according to any one of [1] to [5], wherein the second particles are hollow silica particles or hollow glass particles.

[7] The composition according to any one of [1] to [6], wherein the average particle diameter of the second particles is 1 to 100 μm.

[8] The composition according to any one of [1] to [7], wherein the third particles are boron nitride particles, silicon nitride particles, or aluminum nitride particles.

[9] The composition according to any one of [1] to [8], wherein the third particles have an average particle diameter of 1 to 50 μm.

[10] The composition according to any one of [1] to [9], wherein the third particles are particles surface-treated with a silane coupling agent.

[11] The composition according to any one of [1] to [10], wherein the average particle diameter of the first particles is smaller than either the average particle diameter of the second particles or the average particle diameter of the third particles.

[12] The composition according to any one of [1] to [11], wherein the ratio of the average particle diameter of the second particles to the average particle diameter of the third particles is 0.5 to 3.

[13] The composition according to any one of [1] to [12], which is used to obtain a molded product having a dielectric constant of 2.8 or less and a dielectric loss tangent of 0.0025 or less.

[14] A method for producing a sheet, wherein the composition of any one of [1] to [13] is extruded to obtain a sheet containing the tetrafluoroethylene polymer, the second particles, and the third particles.

[15] The composition of any one of [1] to [13] is disposed on the surface of a substrate, and a polymer layer containing the tetrafluoroethylene polymer, the second particles, and the third particles is formed, A method for producing a laminate, comprising obtaining a laminate having a base material layer composed of the above base material and the polymer layer.

According to the present invention, a composition containing particles of a tetrafluoroethylene-based polymer, hollow particles, and particles of a predetermined inorganic compound, and having excellent dispersibility is provided. From such a composition, it is possible to form a molded article with a low coefficient of linear expansion, dielectric constant, and low dielectric loss tangent, excellent thermal conductivity and adhesiveness, and a particularly low dielectric loss tangent.

The following terms have the following meanings.

“Average particle diameter (D50)” is the cumulative 50% diameter based on the volume of particles determined by laser diffraction/scattering method. That is, the particle size distribution is measured by a laser diffraction/scattering method, a cumulative curve is obtained with the total volume of the particle population being 100%, and the point on the cumulative curve at which the cumulative volume is 50% is the particle size.

The D50 of the particles is determined by dispersing the particles in water and analyzing them by a laser diffraction/scattering method using a laser diffraction/scattering type particle size distribution measuring device (LA-920 measuring instrument manufactured by Horiba Seisakusho Co., Ltd.).

“D90” is the cumulative volume particle diameter of the particles, and is the volume-based cumulative 90% diameter of the particles, obtained in the same manner as “D50”.

“Melting temperature” is the temperature corresponding to the maximum value of the melting peak of the polymer measured by differential scanning calorimetry (DSC).

“Glass transition point (Tg)” is a value measured by analyzing a polymer using a dynamic viscoelasticity measurement (DMA) method.

“Viscosity” is determined by measuring the composition at 25°C using a B-type viscometer and with a rotation speed of 30 rpm. The measurement is repeated three times, and the average value of the three measurements is taken.

“Tixo ratio” is a value calculated by dividing the viscosity η ₁ of the composition measured under conditions where the rotation speed is 30 rpm by the viscosity η ₂ measured under conditions where the rotation speed is 60 rpm. Each viscosity measurement is repeated three times, and the average value of the three measurements is taken.

“Unit” in a polymer means an atomic group based on one molecule of the monomer formed by polymerization of the monomer. The unit may be a unit formed directly through a polymerization reaction, or may be a unit in which a part of the unit is converted into a different structure by processing the polymer. Hereinafter, the unit based on monomer a is also simply described as “monomer a unit.”

The composition of the present invention (hereinafter also referred to as “this composition”) contains first particles of a tetrafluoroethylene-based polymer (hereinafter also referred to as “F polymer”), hollow second particles, and an aspect ratio of 1. and third particles of an inorganic compound in excess. The ratio of the volume concentration of the first particles to the volume concentration of the second particles is greater than 1, and the ratio of the volume concentration of the third particles to the volume concentration of the second particles is less than 0.6.

This composition has excellent dispersibility, has high physical properties of the F polymer, second particles, and third particles, has a low linear expansion coefficient, dielectric constant, and dielectric loss tangent, and has excellent thermal conductivity and adhesiveness. It is easy to form moldings with particularly low loss tangents. The reason is not necessarily clear, but is thought to be as follows.

While hollow particles lower the dielectric constant and dielectric loss tangent of a molded product containing such hollow particles due to the air they contain, they are prone to breakage, making it difficult for the molded product to fully express its physical properties. Therefore, in the present composition, the volume concentration of the low-hardness and low-sliding F polymer particles (first particles) is higher than the volume concentration of the hollow particles (second particles), and the stress applied to the second particles in the present composition is cushioned by the first particles to suppress breakage of the second particles. In particular, when this composition is processed and molded, this inhibitory effect tends to become significant.

Additionally, the present composition contains particles (third particles) of an inorganic compound having an aspect ratio greater than 1 in a ratio less than a predetermined amount relative to the volume concentration of the second particles. It is thought that the third particles contained in such an excessive amount are less likely to aggregate and form a state in which they are easily dispersed uniformly with the first particles and the second particles. In addition, when processing and molding the present composition, dense packing of the excessively contained second particles proceeds, which promotes a high degree of orientation of the third particles in the molded article, in other words, the third particles in the molded article. It is also thought that the formation of a heat conduction path is promoted.

As a result, it is believed that a molded article having high physical properties of the F polymer, second particles, and third particles, specifically, low linear expansion coefficient, dielectric constant, and dielectric loss tangent, and excellent thermal conductivity and adhesiveness was obtained from this composition. .

The F polymer in the present invention is a polymer containing a unit (hereinafter also referred to as “TFE unit”) based on tetrafluoroethylene (hereinafter also referred to as “TFE”). The F polymer may be heat-fusible or non-heat-fusible.

A heat-meltable polymer refers to a polymer at which a melt flow rate is 1 to 1000 g/10 min under the condition of a load of 49 N.

A non-heat meltable polymer means a polymer at which there is no temperature at which the melt flow rate is 1 to 1000 g/10 min under the condition of a load of 49 N.

The melting temperature of the heat-meltable F polymer is preferably 200°C or higher, and more preferably 260°C or higher. The melting temperature of the F polymer is preferably 325°C or lower, and more preferably 320°C or lower. The melting temperature of the F polymer is preferably 200 to 320°C. In this case, the composition tends to have excellent processability, and the molded article formed from the composition tends to have excellent heat resistance.

The glass transition point of the F polymer is preferably 50°C or higher, and more preferably 75°C or higher. The glass transition point of the F polymer is preferably 150°C or lower, and more preferably 125°C or lower.

The fluorine content of the F polymer is preferably 70% by mass or more, and more preferably 72 to 76% by mass.

The surface tension of F polymer is preferably 16 to 26 mN/m. In addition, the surface tension of the F polymer can be measured by placing a droplet of the liquid mixture for the wetting tension test (manufactured by Wako Pure Chemical Industries, Ltd.) specified in JIS K 6768 on a flat plate made of the F polymer.

F polymers include polytetrafluoroethylene (PTFE), polymers containing TFE units and ethylene-based units, polymers containing TFE units and propylene-based units, TFE units and perfluoro(alkyl vinyl ethers) ) (PAVE), polymers containing units based on (PAVE) (PAVE units), polymers containing TFE units and units based on hexafluoropropylene (FEP) are preferred, PFA and FEP are more preferred, PFA is more preferred. These polymers may further contain units based on other comonomers.

As PAVE, CF ₂ =CFOCF ₃ , CF ₂ =CFOCF ₂ CF ₃ and CF ₂ =CFOCF ₂ CF ₂ CF ₃ (hereinafter also referred to as “PPVE”) are preferable, and PPVE is more preferable.

The F polymer preferably has an oxygen-containing polar group, more preferably has a hydroxyl group-containing group or a carbonyl group-containing group, and even more preferably has a carbonyl group-containing group.

In this case, the first particles are likely to interact with the second particles and third particles, and the composition is likely to have excellent dispersibility. In addition, from this composition, it is easy to obtain a molded article with a low coefficient of linear expansion, dielectric constant, and dielectric loss tangent, and excellent thermal conductivity and adhesiveness.

As the hydroxyl group-containing group, a group containing an alcoholic hydroxyl group is preferable, and -CF ₂ CH ₂ OH and -C(CF ₃ ) ₂ OH are more preferable.

Carbonyl group-containing groups include carboxyl group, alkoxycarbonyl group, amide group, isocyanate group, carbamate group (-OC(O)NH ₂ ), acid anhydride residue (-C(O)OC(O)-), and imide residue ( -C(O)NHC(O)-, etc.) and carbonate groups (-OC(O)O-) are preferred, and acid anhydride residues are more preferred.

When the F polymer has an oxygen-containing polar group, the number of oxygen-containing polar groups in the F polymer is preferably 10 to 5,000, more preferably 100 to 3,000, per 1 × 10 ⁶ carbon atoms in the main chain. In addition, the number of oxygen-containing polar groups in the F polymer can be quantified by the composition of the polymer or the method described in International Publication No. 2020/145133.

The oxygen-containing polar group may be contained in a unit based on a monomer in the F polymer or may be contained in a terminal group of the main chain of the F polymer, with the former being preferred. Examples of the latter embodiment include F polymers having oxygen-containing polar groups as terminal groups derived from polymerization initiators, chain transfer agents, etc., and F polymers obtained by plasma treatment or ionizing radiation treatment of F polymers.

As monomers having a carbonyl group-containing group, itaconic anhydride, citraconic anhydride, and 5-norbornene-2,3-dicarboxylic anhydride (hereinafter also referred to as “NAH”) are preferable, and NAH is more preferable. do.

The F polymer is preferably a polymer having a carbonyl group-containing group, including a TFE unit and a PAVE unit, and includes a TFE unit, a PAVE unit, and a unit based on a monomer having a carbonyl group-containing group, and these units are included for all units. It is more preferable that it is a polymer containing 90 to 99 mol%, 0.99 to 9.97 mol%, and 0.01 to 3 mol% in this order. Specific examples of such F polymers include the polymer described in International Publication No. 2018/16644.

The first particles in the present invention are F polymer particles and are non-hollow particles. The first particles may be in the form of pellets.

D50 of the first particle is preferably 0.01 μm or more, more preferably 0.3 μm or more, and still more preferably 1 μm or more. The D50 of the first particles is preferably less than 10 μm, and more preferably less than 8 μm. In this case, the composition tends to have excellent dispersibility and processability. In addition, from this composition, it is easy to obtain a molded article with a low coefficient of linear expansion, dielectric constant, and dielectric loss tangent, and excellent thermal conductivity and adhesiveness.

The specific surface area of the first particles is preferably 1 to 25 m2/g.

The first particles are preferably particles of a heat-meltable F polymer, and more preferably are particles of a heat-meltable F polymer having an oxygen-containing polar group and having a melting temperature of 200 to 320°C.

In this case, the buffering action of the stress of the first particle in the above-described action mechanism is likely to increase. Additionally, the interaction between different types of particles increases, agglomeration of individual particles is easily suppressed, and the dispersibility of the present composition is likely to improve.

This composition may contain two or more types of first particles. Specifically, for example, a composition containing two or more types of first particles with different F polymers, a composition containing two or more types of first particles with different presence or absence of subcomponents described later and different types of subcomponents, and 2 with different D50s. and a composition containing first particles derived from more than one type of first particle powder. In an embodiment in which the present composition contains two or more types of first particles, a composition containing two or more types of first particles with different F polymers is preferred.

When the present composition is a composition containing two or more types of first particles of different F polymers, it is preferable that at least one type of the two or more types of first particles is a particle of the heat-meltable F polymer.

When the composition contains two types of first particles, the composition preferably contains particles of heat-meltable F polymer and particles of non-heat-meltable F polymer as the first particles. In this case, the buffering action and aggregation-inhibiting action of the second particles by the particles of the heat-meltable F polymer and the holding action of the second and third particles by fibrillation of the non-heat-meltable F polymer are balanced, The dispersibility of the present composition is likely to be improved. In addition, in the molded product obtained therefrom, the electrical properties of the non-heat-meltable F polymer are highly expressed, and in particular, a molded product with a low dielectric loss tangent is easy to obtain.

As the former particles, particles of heat-meltable F polymer having a melting temperature of 200 to 320°C are preferable, and particles of heat-meltable F polymer having a melting temperature of 200 to 320°C and having an oxygen-containing polar group are more preferable. . The preferred embodiment of the heat-meltable F polymer having an oxygen-containing polar group in the former particle is the same as the preferred embodiment of the F polymer having an oxygen-containing polar group described above.

As the latter particles, particles of non-heat meltable PTFE are preferred.

Additionally, the volume concentration of the former particles relative to the total volume of the two types of first particles is preferably 50 volume% or less, and more preferably 25 volume% or less. Moreover, the volume concentration is preferably 0.1 volume% or more, and more preferably 1 volume% or more.

In addition, the former particles preferably have a D50 of 1 to 4 μm, and the latter particles preferably have a D50 of 0.1 to 1 μm.

The first particles are particles containing F polymer, and are preferably made of F polymer.

The first particle may contain a resin or an inorganic compound other than the F polymer, or may form a core-shell structure with the F polymer as the core and a resin or an inorganic compound other than the F polymer as the shell, or may have the F polymer as the shell. and may form a core-shell structure with a resin other than F polymer or an inorganic compound as the core.

Here, resins other than F polymer include aromatic polyester, polyamidoimide, polyimide, and maleimide, and examples of inorganic compounds include silica and boron nitride.

The second particles in the present invention are hollow particles. This composition may contain two or more types of second particles. The shape of the second particles may be spherical, needle-shaped (fibrous), or plate-shaped, and is preferably spherical. In this case, the composition tends to have excellent dispersibility and processability. Additionally, it is easy to obtain molded articles with excellent electrical properties from this composition.

The spherical second particles are preferably substantially spherical. A roughly spherical shape means that when the particles are observed with a scanning electron microscope (SEM), the proportion of particles having a ratio of the minor axis to the major axis of 0.7 or more is 95% or more.

The second particles may be resin particles or inorganic particles, and are preferably inorganic particles. In this case, it is easy to obtain a molded article excellent in electrical properties, thermal conductivity, and low linear expansion from this composition.

Resins in the resin particles include cured products of curable resins such as heat-resistant thermoplastic resins and thermosetting resins. Specific examples of the thermoplastic resin and curable resin include polyester resins such as liquid crystalline aromatic polyester, polyimide resin, polyamidoimide resin, epoxy resin, maleimide resin, urethane resin, polyphenylene ether resin, and polyphenyl. Examples include lene oxide resin and polyphenylene sulfide resin.

Inorganic substances in the inorganic particles include carbon, inorganic nitride, and inorganic oxide, including carbon fiber, glass, boron nitride, aluminum nitride, beryllia, silica, wollastonite, talc, cerium oxide, aluminum oxide, Magnesium oxide, zinc oxide and titanium oxide are preferred.

As the second particles, hollow glass particles and hollow silica particles are preferable, and hollow glass particles are more preferable. In this case, it is easy to obtain molded articles with excellent electrical properties from this composition.

As the hollow glass particles, hollow borosilicate glass particles and hollow soda-lime borosilicate glass particles are preferable, and hollow soda-lime borosilicate glass particles are more preferable.

Specific examples of hollow silica particles include the “E-SPHERES” series (manufactured by Taiheiyo Cement Co., Ltd.), the “Silinax” series (manufactured by Nittetsu Mining Co., Ltd.), and the “Ecocosphere” series (Emerson & Kaming) manufactured by the company) can be mentioned.

Specific examples of hollow glass particles include “S4630,” “S3240-VS,” “S60HS,” “S32HS,” “iM16K,” and “iM30K” grades of the “Glass Bubbles” series (manufactured by 3M). there is.

The D50 of the second particle is preferably 1 μm or more, more preferably 3 μm or more, and still more preferably 10 μm or more. The D50 of the second particles is preferably 100 μm or less, more preferably 50 μm or less, and still more preferably 20 μm or less.

The true density of the second particles is preferably 0.2 to 1 g/cm3, and more preferably 0.3 to 0.8 g/cm3.

The bulk density of the second particles is preferably 0.1 to 0.5 g/cm3, and more preferably 0.2 to 0.4 g/cm3.

The pressure strength of the second particles is preferably 30 MPa or more, more preferably 100 MPa or more, and still more preferably 150 MPa or more. The upper limit of the pressure strength is preferably 200 MPa. In addition, the internal pressure strength is the internal pressure strength measured in ASTM D 3102-78, and specifically, an appropriate amount of hollow particles are placed in glycerin and pressurized, and the pressure at which the hollow particles are crushed and the volume is reduced by 10% is considered the internal pressure strength.

The surface of the second particle is preferably surface treated with a silane coupling agent.

The silane coupling agent may be partially reacting or may form a polysiloxane skeleton.

As the hydrolyzable silyl group in the silane coupling agent, a monoalkoxysilyl group, dialkoxysilyl group, and trialkoxysilyl group are preferable, and a trialkoxysilyl group is more preferable. The hydrolyzable silyl group may be hydrolyzed.

Organic groups in the silane coupling agent include monovalent groups having vinyl group, epoxy group, styryl group, acryloyloxy group, methacryloyloxy group, amino group, isocyanate group, mercapto group, benzotriazole group, acid anhydride group, etc. Examples of the organic group include a vinyl group, an epoxy group, a benzotriazole group, a phenyl group, or a ureido group, with a monovalent organic group being preferable, and a monovalent organic group having an epoxy group being more preferable. The silane coupling agent may have multiple organic groups of different types, or may have multiple organic groups of the same type.

The silane coupling agent is preferably a compound having a trialkoxysilyl group, a benzotriazole group, or an epoxy group, and more preferably a compound having a trialkoxysilyl group and an epoxy group.

Silane coupling agents include compounds having a benzotriazole group and a trimethoxysilyl group at both ends of the main chain, compounds having three epoxy groups in the main chain and multiple triethoxysilyl groups in the side chain, and siloxane in the main chain. A compound having an amino group structure at both ends of the main chain, a compound having a butadiene structure in the main chain and one acid anhydride group and one trimethoxysilyl group in the side chain, and a compound having an alkoxysiloxane structure in the main chain and multiple side chains. Compounds having an epoxy group can be mentioned.

Silane coupling agents include, specifically, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-isocyanatepropyltriethoxysilane, and N-phenyl- 3-Aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, p-styryltrimethoxysilane, 3-tri Methoxysilylpropylsuccinic anhydride, N-2-(aminomethyl)-8-aminooctyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldiethoxysilane Sidoxypropyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane can be mentioned.

Specific products of silane coupling agent include “KBM-573”, “KBM-403”, “KBM-903”, “KBE-903”, “KBM-1403”, “X-12-967C”, and “X- 12-1214A”, 「 402,” “KBE-403,” “KR-516,” “KBM-303,” “KBM-4803,” “KBM-3063,” and “KBM-13” (all manufactured by Shin-Etsu Chemical Co., Ltd.). .

A method of surface treating the second particles with a silane coupling agent includes mixing a solution containing a silane coupling agent and the second particles, followed by drying. In the mixing treatment, the mixture of the solution and the second particles may be heated or watered to promote the reaction of the silane coupling agent. Additionally, the reaction of the silane coupling agent may be accelerated using a reaction catalyst. Additionally, after drying, the second particles surface-treated with a silane coupling agent may be pulverized or classified.

It is preferable to reduce the sodium content on the surface of the second particles, which are hollow silica particles or hollow glass particles, by immersing them in an alkaline solution or washing them with the alkaline solution. An alkaline solution may include an aqueous ammonium hydroxide solution.

The sodium oxide content on the surface of the second particles, which are hollow silica particles or hollow glass particles, is preferably 1 to 4 mass%. In addition, the above content is determined by XPS surface analysis. In this case, the second particles are likely to interact with the first or third particles, and the composition is likely to have excellent dispersibility and processability. In addition, it is easy to obtain molded products with excellent electrical properties, especially low dielectric loss tangent, from this composition.

The second particles, which are hollow silica particles or hollow glass particles, are preferably surface treated with a silane coupling agent after being immersed or washed in an alkaline solution. In this case, the second particle is likely to interact with the first or third particle.

It is preferable that the second particles are treated at high temperature to remove water. In this case, the water content of the molded product formed from the present composition can be reduced, and it is easy to obtain a molded product with excellent electrical properties.

The temperature for high-temperature treatment is preferably 500 to 1000°C.

The third particles in the present invention are inorganic particles with an aspect ratio exceeding 1, and are non-hollow particles. This composition may contain two or more types of third particles.

The shape of the third particle may be any of spherical shape, needle shape (fibrous shape), or plate shape. Specifically, it may be spherical shape, scaly shape, layered shape, lobed shape, row shape, columnar shape, crown shape, equiaxed shape, lobe shape, or mica shape. , a block shape, a flat shape, a wedge shape, a rosette shape, a mesh shape, or a prismatic shape may be used, and a scale shape is preferable. In this case, the third particles in the molded article formed from the present composition are likely to form a heat conduction path, and the molded article is likely to have excellent thermal conductivity and low linear expansion properties.

The aspect ratio of the third particle is more than 1, preferably 2 or more, and more preferably 5 or more. The aspect ratio is preferably 10000 or less.

Examples of the inorganic substance in the third particle include the same inorganic substance as the inorganic substance in the second particle described above. Specifically, boron nitride, silicon nitride, aluminum nitride, silica, zinc oxide, titanium oxide, talc, steatite, etc. are mentioned. Among them, the third particles are preferably boron nitride particles, silicon nitride particles, and aluminum nitride particles, more preferably boron nitride particles, and even more preferably hexagonal boron nitride.

When the third particles are flaky boron nitride particles, it is believed that the present composition and molded articles formed from the present composition tend to take on a card house structure and form a heat conduction path. As a result, this composition is preferred because it has excellent dispersibility and the molded product is likely to have excellent thermal conductivity and low linear expansion properties.

The D50 of the third particle is preferably 1 μm or more, and is preferably 5 μm or more. The D50 of the third particle is preferably 50 μm or less, more preferably 20 μm or less, and still more preferably 10 μm or less.

This composition may contain third particles derived from two or more types of third particle powders with different D50. In this case, the composition preferably contains coarse particles derived from a third particle powder having a D50 of 10 to 50 μm and fine particles derived from a third particle powder having a D50 of 0.5 to 4 μm. Since the present composition contains coarse particles and fine particles as third particles, fine particles can be filled between the coarse particles, thereby increasing the filling rate of the third particles in the molded article formed from the present composition. When the composition contains coarse particles and fine particles as the third particles, the mixing ratio of the coarse particles is preferably 70% or more, more preferably 75% or more, with respect to the total amount of the third particles. If the coarse particle ratio is within this range, the third particles in the molded product tend to be densely packed.

The surface of the third particle is preferably surface treated with a silane coupling agent. The silane coupling agent includes the same silane coupling agent that can be used for surface treatment of the second particles, and its preferred range and treatment method are the same.

Specific examples of silica particles include the “Admapain” series (manufactured by Admatex) and the “SFP” series (manufactured by Denka).

Specific examples of zinc oxide particles include the “FINEX” series (manufactured by Sakai Chemical Industry Co., Ltd.).

Specific examples of titanium oxide particles include the “Taifake” series (manufactured by Ishihara Sangyo Corporation) and the “JMT” series (manufactured by Teika Corporation).

Specific examples of talc particles include the “SG” series (manufactured by Nippon Talc Co., Ltd.).

Specific examples of steatite particles include the “BST” series (manufactured by Nippon Talc Co., Ltd.).

Specific examples of boron nitride particles include the “UHP” series (manufactured by Showa Denko) and the “GP” and “HGP” grades of the “Dencarboron Nitride” series (manufactured by Denka).

Specific examples of silicon nitride fillers include the “Denka Silicon Nitride” series (manufactured by Denka Corporation) and the “UBE Silicon Nitride” series (manufactured by UBE Corporation).

Specific examples of aluminum nitride fillers include the “High Purity Aluminum Nitride” series (manufactured by Tokuyama) and the “Toyal Tec Filler TFZ” series (manufactured by Toyo Aluminum).

The D50 of the first particle is preferably smaller than either the D50 of the second particle or the D50 of the third particle. The ratio of D50 of the first particle to D50 of the second particle is preferably 0.8 or less, and more preferably 0.5 or less. The ratio is preferably 0.05 or more, and more preferably 0.1 or more.

The ratio of D50 of the first particle to D50 of the third particle is preferably 0.8 or less, and more preferably 0.5 or less. The ratio is preferably 0.1 or more, and more preferably 0.2 or more.

The ratio of the average particle diameter of the second particles to the D50 of the third particles is preferably 3 or less, and more preferably 2.5 or less. The above ratio is preferably 0.5 or more, more preferably 1 or more, and still more preferably 1.5 or more.

The volume concentration of the first particles relative to the total volume of the first particles, second particles, and third particles in the present composition is preferably 40% or more, and more preferably 50% or more. The volume concentration of the first particles is preferably 70% or less.

The volume concentration of the second particles relative to the total volume of the first particles, second particles, and third particles in the present composition is preferably 20% or more, and more preferably 30% or more. The volume concentration of the second particles is preferably 50% or less, and more preferably 40% or less.

The volume concentration of the third particles relative to the total volume of the first particles, second particles, and third particles in the present composition is preferably 5% or more, and more preferably 10% or more. The volume concentration of the third particles is preferably less than 30%, and more preferably 20% or less.

The volume concentration of the first particles, the volume concentration of the second particles, and the volume concentration of the third particles relative to the total volume of the first particles, second particles, and third particles in the composition are, in this order, 40 It is preferable that it is -70%, 20-50%, 5% or more and less than 30%.

The ratio of the volume concentration of the first particles to the volume concentration of the second particles in the present composition is greater than 1, and is preferably 1.2 or more. The above ratio is preferably 5 or less, and more preferably 3 or less.

The ratio of the volume concentration of the third particles to the volume concentration of the first particles in this composition is preferably 0.5 or less, and more preferably 0.4 or less. The ratio is preferably 0.05 or more, and more preferably 0.1 or more.

The ratio of the volume concentration of the third particles to the volume concentration of the second particles in this composition is less than 0.6, and is preferably 0.5 or less. The ratio is preferably 0.1 or more, and more preferably 0.3 or more.

When the volume concentration or volume concentration ratio is in this range, the composition tends to have excellent dispersibility due to the mechanism of action described above. In addition, it is easy to obtain molded articles with low linear expansion coefficient, dielectric constant, and dielectric loss tangent, and excellent thermal conductivity and adhesiveness from this composition.

The composition may further contain a resin different from F polymer. Such other resins may be contained in the present composition as non-hollow particles, or, when the present composition contains a liquid dispersion medium described later, may be contained dissolved or dispersed in the liquid dispersion medium.

Other resins include curable resins such as thermoplastic resins and thermosetting resins. Specific examples of the thermoplastic resin and curable resin include polyester resins such as liquid crystalline aromatic polyester, imide resin, epoxy resin, maleimide resin, urethane resin, polyphenylene ether resin, polyphenylene oxide resin, and polyester resin. and phenylene sulfide resin.

As other resins, aromatic polymers are preferable, and at least one type of aromatic imide polymer selected from the group consisting of aromatic polyimide, aromatic polyamic acid, aromatic polyamidoimide, and precursors of aromatic polyamidoimide is more preferable. The aromatic polymer is preferably included in the present composition as a varnish dissolved in a liquid dispersion medium.

Specific examples of aromatic imide polymers include the “Upia AT” series (manufactured by Ube Kosan Corporation), the “Neoprim (registered trademark)” series (manufactured by Mitsubishi Gas Chemical Corporation), and the “Speakeria (registered trademark)” series (manufactured by Somal Corporation) manufactured),「Q-PILON (registered trademark)」series (manufactured by PI Technology Research Institute),「WINGO」series (manufactured by Wingo Technology),「Tomide (registered trademark)」series (manufactured by T&K TOKA),「KPI -MX" series (manufactured by Kawamura Sangyo Co., Ltd.), "HPC-1000", and "HPC-2100D" (all manufactured by Showa Electric Materials Co., Ltd.).

In the present composition containing other resins, the volume concentration of the other resin relative to the total volume of the first particles, second particles, and third particles is preferably 0.1 volume% or more, and more preferably 1 volume% or more. . The volume concentration is preferably 15 volume% or less, and more preferably 10 volume% or less.

This composition may be in powder form or may be in liquid form including a liquid dispersion medium.

The liquid dispersion medium is preferably a compound that is liquid at 25°C under atmospheric pressure and has a boiling point of 50 to 240°C. This composition may contain two or more types of liquid dispersion medium. When it contains two types of liquid dispersion medium, it is preferable that the two types of liquid dispersion medium are compatible with each other.

The liquid dispersion medium is preferably a compound selected from the group consisting of water, amides, ketones, and esters.

Amides include N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropanamide, and 3-methoxy-N,N-dimethylpropanamide. , 3-butoxy-N,N-dimethylpropanamide, N,N-diethylformamide, hexamethylphosphorictriamide, and 1,3-dimethyl-2-imidazolidinone.

Ketones include acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl n-pentyl ketone, methyl isopentyl ketone, 2-heptanone, cyclopentanone, cyclohexanone, and cycloheptanone. there is.

Esters include methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, 3-ethoxyethyl propionate, γ-butyrolactone, γ- Examples include valerolactone.

When this composition contains a liquid dispersion medium, the content of the liquid dispersion medium is preferably 40 volume% or more, and more preferably 60 volume% or more. The content of the liquid dispersion medium is preferably 90 volume% or less, and more preferably 80 volume% or less.

When this composition contains a liquid dispersion medium, the solid content concentration in this composition is preferably 20 volume% or more, and more preferably 40 volume% or more. The solid content concentration is preferably 80 volume% or less, and more preferably 70 volume% or less. In addition, solid content refers to the total amount of substances that form solid content in a molded article formed from this composition. Specifically, the first particles, second particles, and third particles are solid content, and when this composition contains other resins, the other resins are also solid content, and the total volume concentration of these components is the solid content concentration in the present composition. It becomes.

When the composition contains a liquid dispersion medium, it is preferable that the composition further contains a nonionic surfactant from the viewpoint of improving the dispersion stability of the first particles, second particles and third particles.

As nonionic surfactants, glycol-based surfactants, acetylene-based surfactants, silicone-based surfactants and fluorine-based surfactants are preferred, and silicone-based surfactants are more preferred. Two or more types of nonionic surfactants may be used. When two types of nonionic surfactants are included, the nonionic surfactants are preferably a silicone-based surfactant and a glycol-based surfactant.

Specific examples of nonionic surfactants include “Ptagent” series (manufactured by Neos), “Supron” series (manufactured by AGC Semichemicals), “Megapac” series (manufactured by DIC), and “Unidyne”. ” series (manufactured by Daikin Industries), “BYK-347”, “BYK-349”, “BYK-378”, “BYK-3450”, “BYK-3451”, “BYK-3455”, “BYK-3456” (manufactured by Big Chemi Japan), “KF-6011”, “KF-6043” (manufactured by Shin-Etsu Chemical Co., Ltd.), “Tergitol” series (manufactured by Dow Chemical Company, “Tergitol TMN-100 .

When this composition contains a nonionic surfactant, the content of the nonionic surfactant in this composition is preferably 1 to 15% by volume.

It is preferable that the composition further contains a silane coupling agent. In this case, the binding force of the first particles, second particles, and third particles is improved, and it is easy to form a molded article in which the falling off of particles is suppressed from the present composition.

The silane coupling agent includes the same silane coupling agent that may be used for surface treatment of the second particles, and its preferable range is also the same.

When this composition contains a silane coupling agent, the content of the silane coupling agent in this composition is preferably 1 to 10% by volume.

This composition also contains a thixotropic agent, a viscosity modifier, an antifoaming agent, a dehydrating agent, a plasticizer, a weathering agent, an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, a whitening agent, a colorant, a conductive agent, a mold release agent, a surface treatment agent, a flame retardant, and a conductive agent. It may contain fillers and other additives such as various fillers.

When the composition is liquid and contains a liquid dispersion medium, the viscosity is preferably 10 mPa·s or more, and more preferably 100 mPa·s or more. The viscosity of this composition is preferably 10000 mPa·s or less, and more preferably 3000 mPa·s or less.

When the composition is liquid and contains a liquid dispersion medium, the thicc ratio is preferably 1.0 to 3.0.

When this composition contains water as a liquid dispersion medium, the pH is more preferably 8 to 10 from the viewpoint of improving long-term storage. The pH of this composition can be adjusted with a pH adjuster (amine, ammonia, citric acid, etc.) or a pH buffer (tris(hydroxymethyl)aminomethane, ethylenediaminetetraacetic acid, ammonium bicarbonate, ammonium carbonate, ammonium acetate, etc.). You can.

This composition is obtained by mixing the first particles, second particles, and third particles with other resins, liquid dispersion media, surfactants, silane coupling agents, additives, etc. as necessary.

This composition may be obtained by mixing the first particles, second particles, and third particles all at once, or may be mixed separately and sequentially, or these master batches may be prepared in advance and mixed with the remaining components. The order of mixing is not particularly limited, and the mixing method may be batch mixing or may be mixed in multiple batches.

Mixing devices for obtaining the present composition include stirring devices with blades such as Henschel mixers, pressure kneaders, Banbury mixers, and planetary mixers, ball mills, attritors, basket mills, sand mills, sand grinders, dyno mills, and dispersions. Grinding equipment equipped with media such as fur mat, SC mill, spike mill and agitator mill, microfluidizer, nanomizer, altimer, ultrasonic homogenizer, dissolver, disper, high-speed impeller, thin film gyratory high-speed A dispersing device equipped with other mechanisms such as a mixer, a rotating/revolving stirrer, and a V-type mixer may be included.

A preferred method for producing the composition containing a liquid dispersion medium includes pre-kneading the first particles and a part of the liquid dispersion medium to obtain a kneaded product, and then adding the kneaded product to the remaining liquid dispersion medium to obtain the present composition. I can hear it. The liquid dispersion medium used during kneading and addition may be the same type of liquid dispersion medium or may be a different type of liquid dispersion medium. The second particles, third particles, different resins, surfactants, silane coupling agents, and additives may be mixed during kneading, or may be mixed when adding the kneaded product to the liquid dispersion medium.

The kneaded product obtained by kneading may be in the form of a paste (such as a paste with a viscosity of 1,000 to 100,000 mPa·s) or in the form of a wet powder (such as a wet powder with a viscosity of 10,000 to 100,000 Pa·s as measured by a capillograph). You can continue.

In addition, the viscosity measured by the capillary graph uses a capillary with a capillary length of 10 mm and a capillary radius of 1 mm, the furnace body diameter is 9.55 mm, and the load cell capacity is 2 t, This value is measured at a temperature of 25°C and a shear rate of 1 s ^-1 .

The mixing in kneading is preferably performed using a planetary mixer. A planetary mixer is a stirring device having two axes of stirring blades that rotate and rotate with each other.

Mixing during addition is preferably performed with a thin-film turning type high-speed mixer. The thin film swirling type high-speed mixer is a stirring device that spreads the first particles and the liquid dispersion medium into a thin film on the inner wall of a cylindrical stirring tank, swirls it, and mixes them while applying centrifugal force.

From this composition, it is easy to obtain a molded article having a dielectric constant of 2.8 or less and a dielectric loss tangent of 0.0025 or less by the mechanism of action described above. The dielectric constant of the molded product is preferably 2.4 or less, and more preferably 2.0 or less. Additionally, it is preferable that the dielectric constant is greater than 1.0. The dielectric loss tangent of the molded product is preferably 0.0022 or less, and more preferably 0.0020 or less. Additionally, the dielectric loss tangent is preferably greater than 0.0010.

When this composition is subjected to a molding method such as extrusion, a molded product such as a sheet is obtained.

When the composition is liquid and contains a liquid dispersion medium, it is preferable to extrude the composition into a sheet. The sheet obtained by extrusion may be further made flexible by press molding, calendar molding, etc. It is preferable to further heat the sheet to remove the liquid dispersion medium and bake the F polymer.

When the composition is in powder form, it is preferable to melt-extrude the composition. Extrusion molding can be performed using a single screw extruder, multi-screw extruder, etc.

Additionally, a molded product may be obtained by injection molding this composition.

When forming a molded product, the composition may be melt-extruded or injection-molded directly, or the composition may be melt-kneaded into pellets, and the pellets may be melt-extruded or injection-molded to obtain a molded product such as a sheet.

The thickness of the sheet obtained from this composition is preferably 25 μm or more, more preferably 30 μm or more, and still more preferably 40 μm or more. The thickness of the sheet is preferably 200 μm or less.

The preferable ranges of the dielectric constant and dielectric loss tangent of the sheet are the same as the ranges of the dielectric constant and dielectric loss tangent of the molded product described above, respectively.

The linear expansion coefficient of the sheet is preferably 100 ppm/°C or lower, and more preferably 80 ppm/°C or lower. The lower limit of the linear expansion coefficient of the sheet is 30 ppm/°C. In addition, the linear expansion coefficient means the value obtained by measuring the linear expansion coefficient of the test piece in the range of 25°C or more and 260°C or less according to the measurement method specified in JIS C 6471:1995.

The thermal conductivity of the sheet in the in-plane direction is preferably 1.0 W/m·K or more, and more preferably 3.0 W/m·K or more. The upper limit of sheet thermal conductivity is 20 W/m·K.

By stacking such sheets on a substrate, a laminate can be formed. Methods for producing a laminate include a method of extruding the present composition together with the raw materials of the base material using a co-extruder as the extruder, a method of extruding the present composition on the base material, and thermal compression bonding of the sheet and the base material. Methods, etc. may be mentioned.

As a base material, a metal substrate (metal foil of copper, nickel, aluminum, titanium, their alloys, etc.), heat-resistant resin film (polyimide, polyamide, polyetheramide, polyphenylene sulfide, polyallyl ether ketone, polyamideimide) , heat-resistant resin films such as liquid crystalline polyester and tetrafluoroethylene polymers), prepreg substrates (precursors of fiber-reinforced resin substrates), ceramic substrates (ceramics substrates such as silicon carbide, aluminum nitride, and silicon nitride), and glass substrates. I can hear it.

The shape of the base material includes planar shape, curved shape, and uneven shape. Additionally, the shape of the base material may be any of thin, plate, film, or fibrous shapes.

The 10-point average roughness of the surface of the substrate is preferably 0.01 to 0.05 μm.

The surface of the substrate may be surface treated with a silane coupling agent or may be plasma treated. Such silane coupling agents include 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-methacryloxypropyltri. A silane coupling agent having a functional group such as ethoxysilane or 3-isocyanate propyltriethoxysilane is preferred.

The peel strength between the sheet and the base material is preferably 10 N/cm or more, and more preferably 15 N/cm or more. The peeling strength is preferably 100 N/cm or less.

By disposing this composition on the surface of a substrate and forming a polymer layer containing F polymer and second particles and third particles, a laminate having a substrate layer composed of the substrate and a polymer layer can be obtained.

The polymer layer is preferably formed by placing the composition containing the liquid dispersion medium on the surface of the substrate, heating to remove the dispersion medium, and further heating to bake the F polymer.

The base material includes the same base material that can be laminated with the sheet described above, and its preferred embodiments are also the same.

Methods for disposing the composition include a coating method, a droplet discharge method, and a dipping method, and roll coating, knife coating, bar coating, die coating, or spraying are preferred.

Heating when removing the liquid dispersion medium is preferably performed at 100 to 200°C for 0.1 to 30 minutes. In the heating at this time, it is not necessary to completely remove the liquid dispersion medium, but it can be removed to the extent that the layer formed by the packing of the first particles, second particles, and third particles can maintain a self-supporting film. Additionally, during heating, air may be sprayed to promote removal of the liquid dispersion medium by air drying.

Heating during firing of the F polymer is preferably performed at a temperature higher than the firing temperature of the F polymer, and is more preferably performed at 360 to 400°C for 0.1 to 30 minutes.

Heating devices for each heating include an oven and a ventilation drying furnace. The heat source in the device may be a contact heat source (hot air, a hot plate, etc.) or a non-contact heat source (infrared rays, etc.).

In addition, each heating may be performed under normal pressure or under reduced pressure.

Additionally, the atmosphere for each heating may be an air atmosphere or an inert gas (helium gas, neon gas, argon gas, nitrogen gas, etc.) atmosphere.

The polymer layer is formed through the process of placing and heating the composition. These steps may be performed once or may be repeated two or more times. For example, the composition may be placed on the surface of a substrate and heated to form a polymer layer, and the composition may be placed on the surface of the polymer layer and heated to form a second polymer layer. Additionally, in the step where the liquid dispersion medium is removed by placing the composition on the surface of the substrate and heating, the composition may be further placed on the surface and heated to form a polymer layer.

This composition may be disposed on only one surface of the substrate or on both surfaces of the substrate. In the former case, a laminate having a base material layer and a polymer layer on one surface of the base layer is obtained, and in the latter case, a laminate having a base layer and a polymer layer on both surfaces of the base layer is obtained. Lose.

Preferred specific examples of the laminate include a metal foil and a metal-clad laminate having a polymer layer on at least one surface of the metal foil, a polyimide film, and a multilayer film having a polymer layer on both surfaces of the polyimide film. I can hear it.

The preferred ranges of the thickness of the polymer layer, dielectric constant, dielectric loss tangent, coefficient of linear expansion, thermal conductivity in the in-plane direction, and peel strength between the polymer layer and the base material layer are the thickness, dielectric constant, and dielectric strength of the sheet obtained from the composition described above. It is the same as the desirable range of loss tangent, coefficient of linear expansion, thermal conductivity in the in-plane direction, and peel strength between the sheet and the base material.

This composition is useful as a material for providing insulation, heat resistance, corrosion resistance, chemical resistance, water resistance, impact resistance, and thermal conductivity.

Specifically, this composition is used in printed wiring boards, thermal interface materials, power module substrates, coils used in power devices such as motors, vehicle engines, heat exchangers, vials, syringes, ampoules, medical wires, Secondary batteries such as lithium ion batteries, primary batteries such as lithium batteries, radical batteries, solar cells, fuel cells, lithium ion capacitors, hybrid capacitors, capacitors, condensers (aluminum electrolytic capacitors, tantalum electrolytic capacitors, etc.), electrochromic It can be used for elements, electrochemical switching elements, electrode binders, electrode separators, and electrodes (positive electrode, negative electrode).

Additionally, this composition is also useful as an adhesive for bonding parts. Specifically, this composition is used for adhesion of ceramic parts, adhesion of metal parts, adhesion of electronic components such as IC chips, resistors, and condensers in substrates of semiconductor elements and module parts, adhesion of circuit boards and heat sinks, and LED chips. It can be used for adhesion to a substrate.

Additionally, the present composition containing a conductive filler can also be suitably used in applications requiring conductivity, for example, in the field of printed electronics. Specifically, it can be used in the manufacture of current-carrying elements in printed circuit boards, sensor electrodes, etc.

Molded articles, sheets, and laminates formed from this composition are useful as antenna parts, printed boards, aircraft parts, automobile parts, sports equipment, food industry products, heat dissipation parts, paints, cosmetics, etc.

Specifically, electric wire covering materials (aircraft wires, etc.), enamel wire covering materials used in motors such as electric vehicles, electrical insulating tape, insulating tape for oil drilling, oil transport hoses, hydrogen tanks, materials for printed boards, separators (precision Filtration membranes, ultrafiltration membranes, reverse osmosis membranes, ion exchange membranes, dialysis membranes, gas separation membranes, etc.), electrode binders (for lithium secondary batteries, fuel cells, etc.), copy rolls, covers for furniture, car dashboards, home appliances, etc., sliding members (loads) bearings, yaw bearings, sliding shafts, valves, bearings, bushes, seals, thrust washers, wear rings, pistons, slide switches, gears, cams, belt conveyors, food transport belts, etc.), tension ropes, wear pads, wear strips, Tube lamps, test sockets, wafer guides, wearing parts of centrifugal pumps, chemical and water supply pumps, tools (shovels, files, awls, saws, etc.), gats of boilers, hoppers, pipes, ovens, baking molds, chutes, rackets, Dies, toilets, container coverings, mounting heat dissipation boards for power devices, heat dissipation members for wireless communication devices, transistors, thyristors, rectifiers, transformers, power MOS FETs, CPUs, heat dissipation fins, metal heat sinks, windmills, wind power generation facilities, aircraft, etc. Blades, casings for personal computers and displays, electronic device materials, interior and exterior of automobiles, sealing materials for processing machines, vacuum ovens, and plasma processing devices that perform heat processing under low oxygen, heat dissipation parts within processing units such as sputtering and various dry etching devices, It is useful as an electromagnetic shield.

Molded articles, sheets, and laminates formed from this composition are useful as electronic board materials such as flexible printed wiring boards and rigid printed wiring boards, protective films, and heat dissipation boards, especially heat dissipation boards for automobiles.

When using a molded product, sheet, or laminate formed from the present composition as a heat dissipation member, the molded product, sheet, or laminate may be bonded directly to the target substrate, or may be bonded to the target substrate through an adhesive layer such as a silicone-based adhesive layer. You can attach it to .

Example

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to these.

1. Preparation of each ingredient

[First particle]

Particle 1: Tetrafluoroethylene-based polymer containing 97.9 mol%, 0.1 mol%, and 2.0 mol% of TFE units, NAH units, and PPVE units in this order, and having 1000 carbonyl group-containing groups per 1 × 10 ⁶ carbon number in the main chain. (Melting temperature: 300 ℃) particles (D50: 2.1 ㎛, specific gravity)

Particle 2: Particles of non-heat meltable polytetrafluoroethylene (D50: 0.3 ㎛, non-porous phase)

Particle 3: Particles (D50: 1.8 μm) of a tetrafluoroethylene polymer (melting temperature: 305°C) containing 98.7 mol% and 1.3 mol% of TFE units and PPVE units in this order, and having no oxygen-containing polar group. specific gravity).

[Second particle]

Particle 4: Soda-lime borosilicate glass particles surface-treated with vinyltrimethoxysilane (D50: 16 ㎛, pressure strength: 180 MPa, spherical, roughly spherical or hollow)

[Third particle]

Particle 5: Boron nitride particles surface-treated with an epoxy group-containing silane coupling agent (D50: 7 ㎛, flaky or non-hollow, aspect ratio: 5 or more)

[Liquid dispersion medium]

NMP: N-methyl-2-pyrrolidone

[Other resins]

Varnish 1: NMP varnish of thermoplastic aromatic polyimide (PI1)

2. Preparation example of composition

[Example 1]

Varnish 1 and NMP were added to the pot and mixed. Additionally, the powder mixture of particle 1, particle 4, and particle 5 was added to the pot and mixed to prepare a mixture. This mixture was kneaded in a planetary mixer and then taken out to obtain soft powder 1 containing particle 1, particle 4, particle 5, PI1 and NMP in a volume ratio of 50:33:17:5:30. Soft powder 1 was in the form of wet powder.

NMP was added to the mixture 1 in multiple portions and stirred while defoaming at 2000 rpm with a planetary mixer. Additionally, NMP was added in multiple portions and stirred to prepare a liquid composition, and composition 1 containing particle 1, particle 4, particle 5, PI1, and NMP in a volume ratio of 50:33:17:5:110 was prepared. got it The viscosity of Composition 1 was 400 mPa·s.

[Example 2]

Except that particle 1 was changed to particle 1 and particle 2, it was the same as example 1, and particle 1, particle 2, particle 4, particle 5, PI1, and NMP were 20:30:33:17:5:110. Composition 2 containing a volume ratio of was obtained. The viscosity of Composition 1 was 500 mPa·s.

[Example 3]

Except that Particle 1 was changed to Particle 3, it was the same as Example 1, and Particle 3, Particle 4, Particle 5, PI1, and NMP were included in this order at a volume ratio of 50:33:17:5:110. Composition 3 was obtained. The viscosity of composition 3 was 500 mPa·s.

[Example 4]

Except that Particle 1 was changed to Particle 3 and the amount of Particle 4 was further changed, it was the same as Example 1, and Particle 3, Particle 4, Particle 5, PI1, and NMP were mixed in this order, 50:50. Composition 4 containing a volume ratio of : 17 : 5 : 110 was obtained. The viscosity of Composition 4 was 900 mPa·s.

[Example 5]

Except that Particle 1 was changed to Particle 3 and the amount of Particle 4 was further changed, it was the same as Example 1, and Particle 3, Particle 4, Particle 5, PI1, and NMP were mixed in this order, 50:25. Composition 5 containing a volume ratio of : 17 : 5 : 110 was obtained. The viscosity of Composition 5 was 300 mPa·s.

In each composition, the ratio between particles, the volume concentration of each particle, and the solid content concentration are summarized in Table 1.

3. Manufacture of laminate

Composition 1 was applied to the surface of a long copper foil with a thickness of 18 μm using a bar coater to form a wet film. Next, the copper foil with the wet film formed was passed through a drying furnace at 110°C for 5 minutes and dried to form a dry film. After that, the copper foil with the dry film was heated at 380°C for 3 minutes in a nitrogen oven. As a result, a laminate 1 having a copper foil and a polymer layer with a thickness of 100 μm containing the melt-fired product of particle 1, particle 4, particle 5, and PI1 on its surface was manufactured.

In the same manner as for Laminate 1, Laminates 2 to 5 were manufactured from Compositions 2 to 5.

4. Evaluation

4-1. Evaluation of the dispersibility stability of the composition

After each composition was stored in a container at 25°C, the dispersibility was visually confirmed, and the dispersion stability was evaluated according to the following standards.

[Evaluation standard]

○: Agglomerates are not recognized.

△: It is recognized that aggregates are also deposited at the bottom of the container. When sheared and stirred, it is uniformly redistributed.

×: It is recognized that aggregates are also deposited at the bottom of the container. Even with shear and agitation, redispersion is difficult.

4-2. Evaluation of peel strength of laminate

A rectangular test piece (length 100 mm, width 10 mm) was cut from each laminate. Then, the position 50 mm from one end in the longitudinal direction of the test piece was fixed, and the copper foil and the polymer layer were peeled from one end in the longitudinal direction at 90° with respect to the test piece at a tensile speed of 50 mm/min.

Then, the maximum load applied at this time was measured as peeling strength (N/cm), and evaluated according to the following standards.

[Evaluation standard]

○: 15 N/cm or more

△: 10 N/cm or more but less than 15 N/cm

×: less than 10 N/cm

4-3. Evaluation of the linear expansion coefficient of the laminate

For each laminate, the copper foil of the laminate was removed by etching with an aqueous ferric chloride solution to produce a sheet as a single polymer layer. A square test piece measuring 180 mm by 180 mm was cut from the manufactured sheet, and the linear expansion coefficient (ppm/°C) of the test piece in the range of 25°C to 260°C was measured according to the measurement method specified in JIS C 6471:1995. Measurements were made and evaluated according to the following standards.

[Evaluation standard]

○: 80 ppm/℃ or less

△: Above 80 ppm/℃ but below 100 ppm/℃

×: exceeding 100 ppm/℃

4-4. Evaluation of the electrical properties of the laminate

A test piece measuring 5 cm x 10 cm was cut from the center of each sheet obtained in the same manner as in 4-3, and the dielectric constant and dielectric loss tangent of the sheet were measured using the SPDR (split post dielectric resonance) method (measurement frequency: 10 GHz). was measured and evaluated according to the following standards.

[Evaluation criteria for dielectric constant]

○: 2.4 or less

△: More than 2.4 but less than 2.8

×: greater than 2.8

[Evaluation criteria for dielectric loss tangent]

○: 0.0020 or less

△: More than 0.0020 but less than 0.0025

×: greater than 0.0025

4-5. Evaluation of thermal conductivity of laminate

A test piece measuring 10 mm x 10 mm was cut from the center of each sheet obtained in the same manner as in 4-3, and the thermal conductivity (W/m·K) in the in-plane direction was measured according to the following standards. evaluated.

[Evaluation standard]

○: 3 W/m·K or more

△: 1 W/m·K or more but less than 13 W/m·K

×: Less than 1 W/m·K

The above results are summarized and shown in Table 2.

As is clear from the above results, this composition has excellent dispersion stability, and the laminate formed from this composition highly expresses the physical properties of the F polymer, the second particle, and the third particle, and has peel strength, low linear expansion, and electrical properties. It had excellent properties and thermal conductivity.

In addition, the entire contents of the specification, patent claims, and abstract of Japanese Patent Application No. 2021-109686 filed on June 30, 2021 are cited here and are incorporated as a disclosure of the specification of the present invention.

Claims (15)

It includes first particles of a tetrafluoroethylene-based polymer, hollow second particles, and third particles of an inorganic compound having an aspect ratio greater than 1, and the volume concentration of the first particles relative to the volume concentration of the second particles. is greater than 1, and the ratio of the volume concentration of the third particles to the volume concentration of the second particles is less than 0.6. According to claim 1,
The volume concentration of the first particles, the volume concentration of the second particles and the volume concentration of the third particles, relative to the total volume of the first particles, the second particles and the third particles, in this order, are 40 -70%, 20-50%, 5% or more and less than 30% of the composition. The method of claim 1 or 2,
The first particles are particles of a heat-meltable tetrafluoroethylene-based polymer, and the heat-meltable tetrafluoroethylene-based polymer is a heat-meltable tetrafluoroethylene-based polymer having an oxygen-containing polar group whose melting temperature is 200 to 320°C. A composition that is a fluoroethylene-based polymer. The method according to any one of claims 1 to 3,
A composition comprising, as the first particles, particles of a heat-meltable tetrafluoroethylene-based polymer and particles of a non-heat-meltable tetrafluoroethylene-based polymer. The method according to any one of claims 1 to 4,
A composition wherein the average particle diameter of the first particles is 0.01 μm or more and less than 10 μm. The method according to any one of claims 1 to 5,
The composition, wherein the second particles are hollow silica particles or hollow glass particles. The method according to any one of claims 1 to 6,
A composition wherein the average particle diameter of the second particles is 1 to 100 μm. The method according to any one of claims 1 to 7,
A composition wherein the third particles are boron nitride particles, silicon nitride particles, or aluminum nitride particles. The method according to any one of claims 1 to 8,
A composition wherein the third particles have an average particle diameter of 1 to 50 μm. The method according to any one of claims 1 to 9,
A composition wherein the third particles are particles surface-treated with a silane coupling agent. The method according to any one of claims 1 to 10,
A composition wherein the average particle diameter of the first particles is smaller than either the average particle diameter of the second particles or the average particle diameter of the third particles. The method according to any one of claims 1 to 11,
A composition wherein the ratio of the average particle diameter of the second particles to the average particle diameter of the third particles is 0.5 to 3. The method according to any one of claims 1 to 12,
A composition used to obtain a molded product having a dielectric constant of 2.8 or less and a dielectric loss tangent of 0.0025 or less. A method for producing a sheet, comprising extruding the composition according to any one of claims 1 to 13 to obtain a sheet containing the tetrafluoroethylene polymer, the second particles, and the third particles. The composition according to any one of claims 1 to 13 is disposed on the surface of a substrate to form a polymer layer comprising the tetrafluoroethylene-based polymer, the second particles, and the third particles, A method for producing a laminate, comprising obtaining a laminate having a substrate layer composed of a substrate and the polymer layer.